Horror series Penny Dreadful premiered last month to decent ratings. Credit: Showtime.

With Dexter gone and Californication on its way out soon enough, CBS (NYSE:CBS) cable subsidiary Showtime needs a new franchise capable of putting up sustainable ratings. Can Penny Dreadful be that series?

Host Ellen Bowman puts this question to analysts Nathan Alderman and Tim Beyers in this week's episode of 1-Up On Wall Street, The Motley Fool's web show in which we talk about the big-money names behind your favorite movies, toys, video games, comics, and more.

Nathan says the show features all the high production value we've come to expect from premium cable original series. Penny Dreadful also has impressive bonafides with screenwriter John Logan writing and executive producing and Academy Award-winning director Sam Mendes executive producing alongside established TV producer Pippa Harris.

Audiences have taken to the show so far. Last month's series premiere drew 1.44 million viewers, better than either Homeland or Masters of Sex. What's more, Penny Dreadful attracted Showtime's youngest audience for a series premiere since Dexter's bow in 2006, Entertainment Weekly reports. These are the sorts of wins that explain why CBS derives 24% of operating income from its cable networks.

Fans chiming in at Rotten Tomatoes -- a little more than 150 as of this writing -- rate the show 92% fresh. Nathan says strong performances from Eva Green and Timothy Dalton, in particular, make it a fun ride for a period horror epic.

While those are no doubt encouraging signs, Tim says that Penny Dreadful has much to live up to. Dexter drew 2.8 million viewers to its season 8 finale. Meanwhile, network president David Nevins has said that Dexter is as important to Showtime as Spider-Man is to Sony (NYSE:SNE). If true, Penny Dreadful is going to need to at least double its viewer base to fill the void.

Now it's your turn to weigh in using the comments box below. Have you seen Penny Dreadful? Does the show's ratings performance surprise you? Click the video to watch as Ellen puts Nathan and Tim on the spot, and then be sure to follow us on Twitter for more segments and regular geek news updates!